Electromagnetic relay



Sept 19, 1961 G. BRAUMANN 3,001,047

ELECTROMAGNETIC RELAY Filed March 24, 1959 United States Patent ELECTROMAGNETIC RELAY Gundokar Braumann, Munich, Germany, assigner to Siemens and Halske Aktiengesellschaft Berlin and Munich, a corporation of Germany Filed Mar. 24, 1959, Ser. No. 801,483 v Claims priority, application GermanyApr. 24, 1958 12 Claims. (Cl. 200-87) This invention is concerned with electromagnetic relays comprising a magnet constructed of. a ilux member `and a core member, an Yarmature the free end of which extends between the pole pieces of the magnet, and a magnetizing winding which is associated with the poles of the magnet and common to the magnet and the armature.

In such relays, the magnet and the armature are disposed with respect to the magnetizing winding in such a manner 'that the armature is upon energization of the winding repulsed from the pole of the iiux member which is in normal position of the armature nearest thereto while being attracted by theoppositely disposed pole of the core member.

In prior relay structures of this type, parts of the iron circuit` are also utilized as electrical conductors. This is preferably effected by placing a circuit which is to be controlled on the armature and on the flux member, respectively, 'whereby the above indicated parts of the magnet are electrically mutually insulated, the armature being electrically separated from these parts. y t

ln a known embodiment, a contact carried by the arma- Y ture cooperates as a make contact with a contact carried by the core member which it engages in Vattracted position of the armature. It is moreover known to dispose upon the core member an individual contact bracket which carries the counter contact cooperating with the armature contact.

IKnown relays are also equipped with break contacts in addition to the above indicated make contacts. For example, there may be provided an additional contact point on the armature for engagement, in normal-:position of the armature, lwith a contact point'disposed upon the lluxl member and thus forming a break contact therewith.

rl`he above last described break contact structure exhibits several disadvantages. While the contact pressure is in the case of the make contact supplied by the attractive force of the magnet, the contact pressure for the break contact must be supplied'by the force of the armature restoring spring. Since the armature must also carry the magnetic flux, itsV cross-sectional area must be considered in the dimensioning thereof so that it suiices for carrying the iiux; that is, when using in known manner an armature constructed in the form of a resilient lamina, its resilience can be related to the contact requirements only insofar as the condition with respect to the carrying of the ilux is satised.

It has been found in many cases that the Contact pressure of sucha break contact cannot satisfy the requiremen-ts in View of the magnetic properties of the armature which have to be met. Attempts have been made to overcome this diiculty by making the flux member of a permanent magnet material, utilizing the permanent flux for exerting a force on the armature in the normal or resting position thereof. This expedient entails considerably increased costs for the corresponding relay structure.

Another disadvantage of this known break contact structure resides in a strong rebounding tendency, consequently chattering, since the kinetic energy of the armature can decay only in a swinging motion in the course of which the contact after it has been closed can be opened again once or several times. llt has been found that this rebounding phenomenon cannot be completely suppressed even by making the llux member of permanent magnet material.

The object of the invention .is to produce, in connection with a relay of the above indicated kind, a break contact which does not exhibit the described disadvantages. This object is realized by providing the relay with a contact spring which is in normal position of the relay in engagement with the structural part carrying the counter-contact for cooperation with the armature contact and causing thisv engagement to be interrupted by the armature in the tracted position thereof.

'Ihe structure according to the invention may be used in connection with relays of the indicated kind, in which the counter-contact yfor cooperation with the armature contact is directly provided on the core member, as well as in connection fWith relays which are in known manner provided with a contact bracket carried upon the core member, such contact bracket carrying the counter-contact for cooperation with the armature contact.

The previously mentioned disadvantages are avoided by the invention. The resilience characteristic of the contact spring may be determined independently of considerations regarding the liux flow and may thus be accurately provided in accordance with given requirements.

A further advantage of the structure and arrangement according to the invention is seen in the fact that twincontact points may be employed which provide advantages as compared with single contact points, while twincontact pointsY provided on the armature would necessitate slotting which would adversely afrect the ilux i'low in the armature and therewith the operation of the relay. v

In accordance vvi-th a further object and feature of the invention, in relays having the individual parts thereof, such as tlux member, core member, contact bracket and armature in known manner assembled in an insulating body, the contact spring can likewise be disposed in a slot v of the corresponding insulating body by atsimple plug-in operation.

Such an insulating body may be advantageously provided with projections for backing the contact spring. As

Vwillbc presently explained more in detail, the use of such projections makes it in particularly advantageous manner possible to place the contact spring in position without requiring adjustment operations, especially when the same projections also serve for backing the core member.

The various objects and yfeatures of the invention will appear in the course of the description of an embodiment of a relay comprising a contact bracket and having its individual parts disposed in layers in an insulating body, which will be rendered below with reference to the accompanying drawing.

In the drawing,

FIG. 1 shows in perspective representation a relay;

FIG. 2 indicates parts in normal or resting position of the relay; and

FIG. 3 indicates the corresponding parts in attracted position of the relay armature.

The relay shown in FIG. l is equipped -With a single iron circuit and its individual parts are disposed in layers in the insulating body 1. The insulating body 1 may be part of a relay bar comprising a plurality of relays. The core member 2 is L-shaped Vand has its long leg inserted in grooves Yformed in the guide chamber 3 of the insulating body. The flux member 4 is formed by a U-shaped structural part the two legs of which are inserted in grooves formed in the guide chambers 3 and 5, in such a manner, that the leg lying in the chamber 3 is positioned adjacent the longer leg of the core member 2, the tree end of the second leg which extends from the chamber 5 overlapping outside of the chamber with the short leg of the core member. The overlapping forms the Working air gap. The armature 6 is made in the formnof a lamina which lies upon the flux member in the chamber '5 so that its free endV is disposed :opposite the short leg of the core member. This armature lamina may be part of the Uzsh'aped resilient sheet metal piece which-is inserted into ithe chamber together with thecore member or Inay 'be with an 'insulating coating. Y

VA contact bracket 8 which is placedupdntheside of the core member 2 facing away from "the armature, .is inserted therewith in grooves formed 'in the guide charnber 3. This contact 'bracket is slotted and extends with its angular portions 9 and 10 into the vspace,'b'etvi/'een the guide chamber and the edgecr the short leg of lthe core member lying-opposite thereto.r

"I'n accordance with the invention,V` there is provided a contact spring 13 which is inserted in `grooves of the guide chamber so as to form a backing for the contacts 11 and y12,. e The ,contact spring extends through the guide chamber, its soldering tab 14 vprojecting rearwardlyvtherefrofm as shown.

The contact spring .is-at litsforward end provided with lateral extensions which rest against projections 15 and 16 at the frontal end of the guide chamber S. FIG. l shows the projection so as to show the structure clearly.

As will be seen from FIGS. 2 ,and 3, the core member also Arestslagainst the identical contact .surfaces ot .these extensions which serve vfor the backing of the contact spring. The ycontact Vspring therefore lies on the same planeY as .the core member; .tolerances accordingly do not appearat. all.

The roperationv of the break .contact shall now be Aexplained with Yreference yto FIGS. 2 and 3 showing parts o'f the relayrcspectively `in non-operated and .in operated position. The various structural parts are referenced in accordance with FIG.` l. n

In FIG. 2,. showing `the arrangement in non-operated position of 4the relay, the armature 6 lies dat on the flux member v4, thearmature being provided with a cylindrical contact point 17. The contacts or 'the contact bracket 8 lrest against the .contact point of the contact spring 13. Accordingly, in Vthis condition of Vthe relay, a circuit is closed whichextends by wayof the-contact bracket A8 and the contact vspring 13.

As :will Abe apparent from FIG. 3, whenthe armature 6 is attracted by `the core member 2, the `contact point 17 ofthe amature-engages the contact point 12 of the contactbrackec-and lifts these contact `points from engage..

ment with the contact spring 13. The corresponding circuit is thus interrupted and another circuit .isV closed ex- Y -tendinglby way-ofthe armature 6 and the contact bracket The abovekdescribed break contact structure operates practically withouttrebcunding .The mass of the armathe break contact. The kinetic-energy remaining in theY contact bracket does lnot produce rebounding or chattering `'of the break-contact but, as has been found, lis dissipated 'by's'winging motion-ofthe :rearward -end 'of the conture 6 is greater than thatof -the ycontact bracket/8; Y

It ymay also 'be mentioned that the contact pointsmiay Y be advanageously coated with noble metal.

The illustrated embodiment may of course be modied.

As will be readily seen,y theinvention may also be applied in connection with relays .of `the described kind the individual Aparts of which are stacked .in layers instead of being inserted into an insulating body. It is also understood that the invention is not limited for use-in connecttion with therdescribed land Aillustrated individual parts including the iron circuit and the contact'r bracket but may be employed in structures diffeng'f-theretrom. For

example, the lluX member may be E-shaped, the core l member and the contact bracket may be U-shaped and provided with correspondingly arranged con-tact extensions or projections.

employ a slotted contact spring so as to make-the twincontact points completely independent of one another.' The backing for the contact spring is not absolutelyV necessary as such spring may extend `freely from the guide chamber.

These and other changes and modifications are accordingly possible within the scope Vand spirit of ithe appended Y Y claims which deline what is believed to 'be new and desired to have protected by Letters Patent.

I claim.: Y Y Y l. An electromagnetic relay comprising "a `magnet including a ux member and a core member, an armature extending with the free .end thereof between the poles of said magnet, a magnetizing winding common to said magnet and said armature, said amature beingutilized as an electrical conductor and closing in its attracted position an ,electrical circuit by Vengagement with contact means .cooperating therewith, a structural member carrying said las-t nameed contact means normally cned adjacent said corelmember, a contact V4spring which is in normal position of `saidarmaturein engagement with said v structural member, movement or `the latter, responsive Y extending with the freegendV 'thereof between the poles of said magnet, a magnetizing winding .common to said Vmagnet `and said armature, sai-d armature being -utiiizfed as an Aelectrical .conductor and closing in i-ts attracted position an electrical circuit by engagementl with contact means cooperating therewith, a structural member carrying said Ylast named contact means, .a contact spring which is in .normal position of said armature in engage-f ment with said structural member, `saidengagement being interrupted responsive to operative actuation of said armature, and 'an insulating body for supporting said magnetizing winding, the individual relay parts. being inserted inV layers .in said insulatingfbody, Vsaid contact -spring 'being linserted into guide means formed in said i insulating body.

tact bracket- 8 v-in .damped manner about its `normal posi- I tion and in part -in contact friction, without `causing any contact opening.

4. An electromagnetic 'relay comprising a magnet including Va-ux member and a core member, an armature extending with the free end; thereof Vbetween thefpoles of said magnet, a magnetizing kwinding common Lto said magnet and vsaid armature, `said-armature -being utilized asxan .electrical conductor and .closing in its attracted position an electrical .circuit by -engagementwith contact means cooperating therewith, ra structural `member carrying said :last named contact means, -a :Contact spring which Lis lininorrnal yposition Vof saidfarmature in engagement v,with said Astructural member, 'said engagement being interrupted responsive to operative actuationlof said armature, a contact bracket cooperating with said core The contact ,spring may likewise assume diierent shapes. kIt is, for example, possible to y contact means, and ra contact member carried by said armature which is operative upon attraction of said armature to lift said contact means carried by said contact bracket from engagement with said contact spring.

5. An electromagnetic relay according to claim 4, comprising an insulating body 'for supporting said magnetizingV winding, the individual relay parts being inserted in layers in said insulating body, said contact spring being inserted into guide means formed in said insulating body.

6. An electromagnetic relay according to claim 3, wherein said Contact spring is widened to form lateral extensions at the forward contact-making endthereof.

7. An electromagnetic relay according to claim 5, wherein said contact spring is widened to form lateral extensions at the forward contact-making end thereof.

8. Anl electromagnetic relay according to claim 6,

wherein said insulating body forms projections for backwherein said insulating body forms projections for backing the lateral extensions of said Vcontact spring.

lO. An electromagnetic relay according to claim 8, wherein said projections are also operative as backings y for said core member.

11. An electromagnetic relay ,according to claim 9, wherein said projections are also operative as backings for said core member.

12. An electromagnetic relay according to claim 4, wherein the contact portion of said contact bracket is provided at an extension which projects in the direction of the contact portion of said contact spring, said portion being `slotted at the free end thereof to provide twin contact points thereat, said slotting extending into said contact bracket. v

References Cited in the le of this patent UNITED STATES PATENTS 2,115,804 Fondiller May 3, 1938 2,275,531 Lakatos Mar. 10, 1942 2,323,961 Zupa July 13, 1943 2,562,091 Harrison July 24, 1951 2,608,630 Harrison Aug. 26, 1952 2,913,551 Vigren et a1 Nov. 12, 1959- 

